apm wrote: Where can I find a guide that conducts me step by step to build a simple community?

I have read some documents about configuration but they do not explain the logic behind creation a social network.

Your best approach would be to create a test site and just install CB 2.0 and experiment.

Each CB 2.0 backend page has its own online help page.

We also have a set of Getting Started articles to go through once you install.

www.joomlapolis.com/documentation/community-builder/getting-started

apm wrote: You open source developers are very nice but always let us staring at space. Try, try, try..waste your time but give your money.

Sorry to be so franky; anyway I will try CB

Sorry - I did not in any way ask you to pay anything - if my answer gave you this impression it was not my intention.

Hope the rest of the community can help you better than I have.